HaiPay Configuration and Signature Guide

/**
 * Generates a 2048-bit RSA key pair and converts the public and private keys to PEM format.
 *
 * @return A Map containing the public and private keys, with keys "publicKey" and "privateKey".
 */
public static Map<String, String> generateRSAKeyPair() {
    try {
        // Create KeyPairGenerator object and specify RSA algorithm
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");

        // Initialize the key length to 2048 bits
        keyPairGenerator.initialize(2048);

        // Generate the key pair
        KeyPair keyPair = keyPairGenerator.generateKeyPair();

        // Retrieve the public and private keys
        PublicKey publicKey = keyPair.getPublic();
        PrivateKey privateKey = keyPair.getPrivate();

        // Convert the public and private keys to PEM format
        String publicKeyPem = convertPublicKeyToPEM(publicKey);
        String privateKeyPem = convertPrivateKeyToPEM(privateKey);

        // Store the public and private keys in a Map
        Map<String, String> keyPairMap = new HashMap<>();
        keyPairMap.put("publicKey", publicKeyPem);
        keyPairMap.put("privateKey", privateKeyPem);
        return keyPairMap;

    } catch (NoSuchAlgorithmException e) {
        throw new RuntimeException("Failed to generate RSA key pair", e);
    }
}

/**
 * Converts the public key to PEM format.
 *
 * @param publicKey The public key object.
 * @return The public key as a PEM formatted string.
 */
private static String convertPublicKeyToPEM(PublicKey publicKey) {
    String encodedPublicKey = Base64.getMimeEncoder(64, "\n".getBytes())
            .encodeToString(publicKey.getEncoded());
    return "-----BEGIN PUBLIC KEY-----\n"
            + encodedPublicKey
            + "\n-----END PUBLIC KEY-----";
}

/**
 * Converts the private key to PEM format.
 *
 * @param privateKey The private key object.
 * @return The private key as a PEM formatted string.
 */
private static String convertPrivateKeyToPEM(PrivateKey privateKey) {
    String encodedPrivateKey = Base64.getMimeEncoder(64, "\n".getBytes())
            .encodeToString(privateKey.getEncoded());
    return "-----BEGIN PRIVATE KEY-----\n"
            + encodedPrivateKey
            + "\n-----END PRIVATE KEY-----";
}

import lombok.extern.slf4j.Slf4j;
import org.apache.tomcat.util.http.fileupload.IOUtils;

import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;

/**
 * @ClassName SHA256WithRSAUtils
 * @Description (SHA256WithRSA Signature Utility Class)
 * @Author Finlay
 * @Date 2021-02-01
 * @Version 1.0.0
 */
@Slf4j
public class SHA256WithRSAUtils {

    public static final Charset CHARSET = StandardCharsets.UTF_8;
    /**
     * Key Algorithm
     */
    public static final String ALGORITHM_RSA = "RSA";
    /**
     * RSA Signature Algorithm
     */
    public static final String ALGORITHM_RSA_SIGN = "SHA256WithRSA";
    public static final int ALGORITHM_RSA_PRIVATE_KEY_LENGTH = 2048;

    private SHA256WithRSAUtils() {
    }

    /**
     * RSA Algorithm Public Key Encryption
     *
     * @param data The plain text string to be encrypted
     * @param key  RSA public key string
     * @return The encrypted cipher text string, encoded in Base64
     */
    public static String buildRSAEncryptByPublicKey(String data, String key) {
        try {
            // Get the public key object through X509-encoded Key instruction
            X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(Base64.getDecoder().decode(key));
            KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
            Key publicKey = keyFactory.generatePublic(x509KeySpec);
            Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            return Base64.getEncoder().encodeToString(rsaSplitCodec(cipher, Cipher.ENCRYPT_MODE, data.getBytes(CHARSET)));
        } catch (Exception e) {
            throw new RuntimeException("An error occurred while encrypting the string [" + data + "]", e);
        }
    }

    /**
     * RSA Algorithm Public Key Decryption
     *
     * @param data The Base64-encoded cipher text string to be decrypted
     * @param key  RSA public key string
     * @return The decrypted plain text string
     */
    public static String buildRSADecryptByPublicKey(String data, String key) {
        try {
            // Get the public key object through X509-encoded Key instruction
            X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(Base64.getDecoder().decode(key));
            KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
            Key publicKey = keyFactory.generatePublic(x509KeySpec);
            Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
            cipher.init(Cipher.DECRYPT_MODE, publicKey);
            return new String(rsaSplitCodec(cipher, Cipher.DECRYPT_MODE, Base64.getDecoder().decode(data)), CHARSET);
        } catch (Exception e) {
            throw new RuntimeException("An error occurred while decrypting the string [" + data + "]", e);
        }
    }

    /**
     * RSA Algorithm Private Key Encryption
     *
     * @param data The plain text string to be encrypted
     * @param key  RSA private key string
     * @return The encrypted cipher text string, encoded in Base64
     */
    public static String buildRSAEncryptByPrivateKey(String data, String key) {
        try {
            // Get the private key object through PKCS#8-encoded Key instruction
            PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(key));
            KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
            Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
            Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
            cipher.init(Cipher.ENCRYPT_MODE, privateKey);
            return Base64.getEncoder().encodeToString(rsaSplitCodec(cipher, Cipher.ENCRYPT_MODE, data.getBytes(CHARSET)));
        } catch (Exception e) {
            throw new RuntimeException("An error occurred while encrypting the string [" + data + "]", e);
        }
    }

    /**
     * RSA Algorithm Private Key Decryption
     *
     * @param data The Base64-encoded cipher text string to be decrypted
     * @param key  RSA private key string
     * @return The decrypted plain text string
     */
    public static String buildRSADecryptByPrivateKey(String data, String key) {
        try {
            // Get the private key object through PKCS#8-encoded Key instruction
            PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(key));
            KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
            Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
            Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            return new String(rsaSplitCodec(cipher, Cipher.DECRYPT_MODE, Base64.getDecoder().decode(data)), CHARSET);
        } catch (Exception e) {
            throw new RuntimeException("An error occurred while decrypting the string [" + data + "]", e);
        }
    }

    /**
     * RSA Algorithm Private Key Digital Signature Generation
     *
     * @param data The plain text string to be signed
     * @param key  RSA private key string
     * @return The Base64-encoded signed string using RSA private key
     */
    public static String buildRSASignByPrivateKey(String data, String key) {
        try {
            // Get the private key object through PKCS#8-encoded Key instruction
            PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(key));
            KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
            PrivateKey privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
            Signature signature = Signature.getInstance(ALGORITHM_RSA_SIGN);
            signature.initSign(privateKey);
            signature.update(data.getBytes(CHARSET));
            return Base64.getEncoder().encodeToString(signature.sign());
        } catch (Exception e) {
            throw new RuntimeException("An error occurred while signing the string [" + data + "]", e);
        }
    }

    /**
     * RSA Algorithm Public Key Signature Verification
     *
     * @param data  The plain text string that was signed
     * @param key   RSA public key string
     * @param sign  The Base64-encoded signature string obtained from RSA signing
     * @return true--signature verified, false--signature verification failed
     */
    public static boolean buildRSAverifyByPublicKey(String data, String key, String sign) {
        try {
            // Get the public key object through X509-encoded Key instruction
            X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(Base64.getDecoder().decode(key));
            KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);
            PublicKey publicKey = keyFactory.generatePublic(x509KeySpec);
            Signature signature = Signature.getInstance(ALGORITHM_RSA_SIGN);
            signature.initVerify(publicKey);
            signature.update(data.getBytes(CHARSET));
            return signature.verify(Base64.getDecoder().decode(sign));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * RSA Algorithm for Chunked Encryption/Decryption of Data
     *
     * @param cipher The javax.crypto.Cipher object initialized with the encryption/decryption mode
     * @param opmode The operation mode (Cipher.ENCRYPT_MODE / Cipher.DECRYPT_MODE)
     * @return The byte array of encrypted or decrypted data
     */
    private static byte[] rsaSplitCodec(Cipher cipher, int opmode, byte[] datas) {
        int maxBlock = 0;
        if (opmode == Cipher.DECRYPT_MODE) {
            maxBlock = ALGORITHM_RSA_PRIVATE_KEY_LENGTH / 8;
        } else {
            maxBlock = ALGORITHM_RSA_PRIVATE_KEY_LENGTH / 8 - 11;
        }
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] buff;
        int i = 0;
        try {
            while (datas.length > offSet) {
                if (datas.length - offSet > maxBlock) {
                    buff = cipher.doFinal(datas, offSet, maxBlock);
                } else {
                    buff = cipher.doFinal(datas, offSet, datas.length - offSet);
                }
                out.write(buff, 0, buff.length);
                i++;
                offSet = i * maxBlock;
            }
        } catch (Exception e) {
            throw new RuntimeException("An error occurred while encrypting/decrypting data with the threshold [" + maxBlock + "]", e);
        }
        byte[] resultDatas = out.toByteArray();
        IOUtils.closeQuietly(out);
        return resultDatas;
    }
}

public static String getSign(Object obj, String secretKey) {
    Map<String, Object> map;
    if (obj instanceof Map) {
        map = (Map<String, Object>) obj;
    } else {
        map = BeanMapTool.beanToMap(obj);
    }
    Set<String> keys = map.keySet();
    List<String> list = new ArrayList<>(keys);
    Collections.sort(list);
    // Construct the format for the signature key-value pair
    StringBuilder sb = new StringBuilder();
    // Construct the format for the signature key-value pair
    for (String key : list) {
        Object val = map.get(key);
        // If the key is not sign_type or sign, and the key is not empty, append it to the signature string.
        if (!("".equals(val) || val == null || List.of("sign_type", "sign").contains(key))) {
            sb.append(key).append("=").append(val).append("&");
        }
    }
    sb.append("key=").append(secretKey);
    return sb.toString();
}



// package com.haipay.admin.utils;
import org.springframework.cglib.beans.BeanMap;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Bean and Map Conversion
 */
public class BeanMapTool {
    public static <T> Map<String, Object> beanToMap(T bean) {
        BeanMap beanMap = BeanMap.create(bean);
        Map<String, Object> map = new HashMap<>();
        beanMap.forEach((key, value) -> map.put(String.valueOf(key), value));
        return map;
    }
}

public static void main(String[] args) {
        String privateKey = "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";
        String publicKey = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAiqoMbM2+Dm7qCeVPA3c9srThRXPNX5p4kRaPo7zbaznoDFKXfYAT7zBGgc3XiQu+AoPx7ABO3/btuADy4tKC2GQsLYYbNNcUyIQIrPIeyGAknVq3G5/IKQe2qUnuFHdHUus5LkXA01RrCza8zTjCh30/Etd3bbKg8gwQYUqZAcHvU5Hi0AfCuWYw2CfLk7bK3HsveXjRXttq/KgIb+etslAUxtD42aUJoiVg9E+lESy8zWBDlxM7FVWYDygTVklWbzIy4N9nhb/9jMPsfN5+OMN/RS8ehN+OwOYVUGFmwS7hw8hVM1v3p3TpjEo9WCZhg4XLYBCvlCANWzW3sWKN9wIDAQAB";
        Map<String, Object> request = new HashMap<>();
        request.put("appId", "1000");
        request.put("orderNo", "1000");
        //Obtain String to Be Signed
        String content = SignUtils.getSign(request, "WFZflvcV75jYP2G6QIpSsMtoX1e4awxO");
        //Execute Signature
        String sign = SHA256WithRSAUtils.buildRSASignByPrivateKey(content, privateKey);
        System.out.println("Signature:" + SHA256WithRSAUtils.buildRSASignByPrivateKey(content, privateKey));
    System.out.println("Verification:" + SHA256WithRSAUtils.buildRSAverifyByPublicKey(content, publicKey, SHA256WithRSAUtils.buildRSASignByPrivateKey(content, privateKey)));
}